/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.io;

import proguard.classfile.*;
import proguard.classfile.io.*;
import proguard.classfile.util.*;
import proguard.classfile.visitor.ClassVisitor;

import java.io.*;

/**
 * This DataEntryReader applies a given ClassVisitor to the class definitions that it reads.
 * <p>
 * Class files are read as ProgramClass objects or LibraryClass objects, depending on the <code>isLibrary</code> flag.
 * <p>
 * In case of libraries, only public classes are considered, if the <code>skipNonPublicLibraryClasses</code> flag is
 * set.
 *
 * @author Eric Lafortune
 */
public class ClassReader implements DataEntryReader {
    private final boolean isLibrary;
    private final boolean skipNonPublicLibraryClasses;
    private final boolean skipNonPublicLibraryClassMembers;
    private final WarningPrinter warningPrinter;
    private final ClassVisitor classVisitor;

    /**
     * Creates a new DataEntryClassFilter for reading the specified Clazz objects.
     */
    public ClassReader(boolean isLibrary, boolean skipNonPublicLibraryClasses, boolean skipNonPublicLibraryClassMembers,
        WarningPrinter warningPrinter, ClassVisitor classVisitor) {
        this.isLibrary = isLibrary;
        this.skipNonPublicLibraryClasses = skipNonPublicLibraryClasses;
        this.skipNonPublicLibraryClassMembers = skipNonPublicLibraryClassMembers;
        this.warningPrinter = warningPrinter;
        this.classVisitor = classVisitor;
    }

    // Implementations for DataEntryReader.

    public void read(DataEntry dataEntry) throws IOException {
        try {
            // Get the input stream.
            InputStream inputStream = dataEntry.getInputStream();

            // Wrap it into a data input stream.
            DataInputStream dataInputStream = new DataInputStream(inputStream);

            // Create a Clazz representation.
            Clazz clazz;
            if (isLibrary) {
                clazz = new LibraryClass();
                clazz.accept(new LibraryClassReader(dataInputStream, skipNonPublicLibraryClasses,
                    skipNonPublicLibraryClassMembers));
            } else {
                clazz = new ProgramClass();
                clazz.accept(new ProgramClassReader(dataInputStream));
            }

            // Apply the visitor, if we have a real class.
            String className = clazz.getName();
            if (className != null) {
                String dataEntryName = dataEntry.getName();
                if (!dataEntryName.equals("module-info.class")
                    && !dataEntryName.replace(File.pathSeparatorChar, ClassConstants.PACKAGE_SEPARATOR)
                        .equals(className + ClassConstants.CLASS_FILE_EXTENSION)
                    && warningPrinter != null) {
                    warningPrinter.print(className, "Warning: class [" + dataEntry.getName()
                        + "] unexpectedly contains class [" + ClassUtil.externalClassName(className) + "]");
                }

                clazz.accept(classVisitor);
            }

            dataEntry.closeInputStream();
        } catch (Exception ex) {
            throw (IOException)new IOException(
                "Can't process class [" + dataEntry.getName() + "] (" + ex.getMessage() + ")").initCause(ex);
        }
    }
}
